Wireless telephony.



V. H. LAUGHTER.

WIRELESS TELEPHONY;

APPLICATION FILED 001'. 20, 1909.

1 m Wu Patented July 8, 1913.

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.Specification of Letters Patent.

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Application filed October 20, 1909. Serial No. 528,826.

To all whom'z'tmag concern:

Be it known that I, VICTOR H. LAUeI-rrnR, a citizen of the United States of America,

residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Wireless Telephony, of which the/following is a specification, reference being had therein to the accompanying drawings.

This invention relatesto Wireless telephony and more particularly to a transmitting apparatus therefor whereby increased efficiency of service is obtained together with simplicity of construction in the apparatus itset'. f

The invention consists in the matters hereinafter set forth, and more particularly pointed out in the, appended claims.

In the drawings, Figure 1 is a diagrammatic illustration of an arrangement of a wireless telephony system that embodies features of the invention; Fig. 2 is a similar view showing a modification in the arrange- 'mcnt; Fig. 3 is a view in longitudinal section of a transmitter condenser; and Fig. 4

is a view in section of a transmitter.

1' for obtaining an oscillatory current of Referring to the drawings, any means at high frequency is connected with a condenser 2 of variable capacity and the primary 3 of .a transformer whose secondary 4 with an antenna and ground (3 constitutes the aerial c rcuit.

A condenser transmitter 7 is in shunt around the primary 3, and the condenser 2 is adjusted to have a sli htly greater capacity than that of the condenser 7. A telephone transmitter 8 with battery 9 is connected with the condenser 7 in such manner that the vibrations set up in the telephone by the voice vary the capacity of the condenser transmitter and in consequence the I oscillations on the primary 3 of the trans the poles thereof held between insu gaskets 14 parallel to a brass plate 15 placed former are varied and thus the antenna circuit is influenced. The condenser transmitter may be of any typeadapted to carry the currents used and in preferred form consists of two oppositely disposed containing casings 10 of insulating material secured by an annular member 11. Each case has a magnet 12 with a diaphragm 13 adiacent ating between the inner ends of the casings. Each magnet has windings 16, which are in series with the battery 9 or the like, and the telephone transmitter 8'. The two' diaphragms 1.3 are connected as alternate plates or a condenser, the brass plate constituting an intermediate plate, with 'air spaces as the dielectric, and this condenser is in shunt around the primary '3, as before described. On speaking into the telephone transmitter 8, the diaphragms 13 are vibrated and consequently the dielectric, between the diaphragms and plate is correspondingly changed. This varies the capacity of the condenser transmitter, and influences the oscillations in'the primary, as above noted. By placing two or more of these condenser transmitters in circuit, any capacity desired may be obtained. -When'used in this manner, it is desirable to'have the windings 16 capable of carrying a current of considerable amperage. This would overheat a telephone transmitter of standard construction. Accordingly, the form of transmitter indicated in :Fig. 4 is preferably used. A .front plate 18 with stan dardQmouthpiece clamps a, diaphragm 19 on a back QO between insulating rings .21. A pocket or cup 22 is filled in thensual manner with granular carbon, that is retained by a inica' slieet 23 holding a contact piece 24 of the diaphragm in place in the usual manner. 'The cup is secured in place by La stem 25 adjustably held 'in a socket of the back. The. latter is hollow and has nipples 2G by which itmay be connected with a convenientsourcc of supply of water or other cooling liquid by flexible tubing. By this arrangement, overheatinowith disintegrating of the carbon graniiles is prevented.

To' prevent air cushioning the diaphragms 13 of the condenser transmitter, an air vent 30 extends through the member 11 and plate 15, and opens i-nto the spaces on each side of the plate.

A modification of the'arrangement of the circuit is indicated in Fig. 2. Herein a condenser transmitter 27 preferably of the construction described, has its plates in series with end portions of the secondary coil 4 of the transformer in the antenna circuit. A resistance coil 28 is in shunt across the end coils of the transformer and has sliding contacts 29 by which the shunt circuit to the condenser transmitter 27 may be adjusted to get the best effects. The voice or sound waves in the transmitter thereby influence other arrangement.

Obviously, changes in details of construction may be made without departing from the spirit of the, invention, and I do not limit myself to any particular form or ar' rangement of parts;

What I claim as my inventionis 1. Space telephony apparatus comprising an energizing circu1t,a secondary antenna circuit responsive to the energizing circuit, a condenser of variable capacity in the ener-. gizing circuit, a telephone transmitter circuit including a condenser having a fixed plate and vibratable plates connected in parallel and in spaced parallel relation to the fixed plate, the condenser being in shunt across the energizing circuit, an electromagnet controlling each vibratable plate, and means in series with the coils of the electromagnets having a resistance that varies in accordance with sound waves impressed thereon.

2. Space telephony apparatus comprising an energizing circuit including the primary ot a transformer, and a condenser of variable capacity, an antenna circuit including the secondary of the transformer, a telephone transmitter circuit in shunt to the primary of the transformer including a condenser having fixed and vibratable plates and field magnets in series with a generator for the transmitter circuit and influencing the vibratable plates together with means in series'with the field magnets having a'resistance that varies in accordance with sound waves impressed thereon. y i 3. Space telephony apparatus comprising an energizing circu1t including in seriesa generator, a primary of a transformer and a condenser of variable capacity, an antenna circuit including. the secondary of the said transformer and a telephone transmitter circu t mshunt to the primary including a con denser consistlng of an insulating casing with fixed and vibratable plates therein connected in shunt across the limbs of the energizing circuit, electro-magnets each controlling a vibratable plate, a generator in series with the coils of thema ets, and a transmitter in series with the 0011s and generator having a resistance that varies in accordance -with sound waves impressed thereon.

4. In space telephony apparatus, a condenser consisting of an insulating casing, a

fixed plate therein, vibratable-plates con nected parallel and in spaced insulated relationth etoi) and an electro-magnet con- 0 0 trolling each .vi ratable plate, and means'in series with th'e'coils having a resistance that" varies in accordance with sound waves 1m pressed thereon. A

5. In space telephony apparatus, a conoperatively connected therewith,rand in circuit with each other, and a microphone in circuit with said electromagnets.

7. The combination with a condenser transmitter, of a plurality of means 0 erat- ,ing simultaneously on an element 0 said condenser, and means to vary the amplitude of the vibrations of said element.

' In testimon whereof I afiixmy signature in presence 0 two witnesses.

VICTOR H. LAUGHTER. Witnesses: I

C. R. STICKNEY, A. M. SHANNON. 

